1. Field of the Invention
The present invention relates to a mounting assistance device of a tire and wheel assembly, and more particularly, to a mounting assistance device of a tire and wheel assembly to accurately align a center of rotation of the assembly with an axle of an automobile when mounting the tire and wheel assembly onto the axle of the automobile.
2. Description of the Related Art
In an operation for mounting the tire and wheel assembly (which may be referred to simply as an assembly hereinafter) to the axle of a vehicle, it is vital to make the center of rotation of the tire and wheel assembly coincide with a central axis of the axle of the vehicle.
However, in this mounting operation, a moment, which tends to move a center of gravity of the assembly downwards from a center of rotation of the axle of the vehicle, always acts because of factors such as the assembly being heavy, the center of gravity of the assembly being offset toward an outside of the vehicle, and the like. As a result, the axle of the vehicle may not coincide with the center of rotation of the assembly and the assembly may end up being mounted to the axle of the vehicle in an eccentric state.
If the vehicle is run with the center of gravity of the assembly being eccentric as described above, because vibrating forces act on the vehicle from unsprung parts, vibration is generated and the tire is unevenly worn.
As a mounting method for avoiding the above-described drawbacks, there has been conventionally used a method in which the assembly is rotated while the tire thereof is tapped, diagonal pairs of one of mounting nuts and wheel bolts are successively tightened little by little until the one of nuts and bolts are not loose, and then final tightening thereof is carried out with a torque wrench.
However, this method depends to a large extent on levels of skill of operators and is not generic.
The present applicant has suggested a mounting assistance device, with which variations between operators are suppressed and an assembly is mounted to the axle of the vehicle with high accuracy without the assembly being caused to be eccentric, and a method thereof (Japanese Patent Application Laid-Open (JP-A) No. 7-228102). As illustrated in FIG. 8, in a mounting assistance device 2, clamping members 8 and 10 abut against both side surfaces (sidewall portions) of a tire 6 of an assembly 4, and a nut 11 is tightened. As a result, an eccentric disc 12 cannot move in directions X with respect to the clamping member 10. When a handle 14 is rotated, the clamping member 8 and the clamping member 10 are caused to approach each other by a cam action of the eccentric disc 12 thereby clamping the tire 6. In this state, rotation of the eccentric disc 12 is disabled by a nut 16. Accordingly, a tightened state is locked so that a fixed state is securely maintained.
Vibration is applied to the assembly 4 in the above-described state by a vibrating device 18. Vibration of the assembly 4 acts to offset eccentricity of the center of rotation of the assembly 4. Accordingly, even if an operator is not skilled, the operator can mount the assembly to the axle of the vehicle with high accuracy by further tightening the one of hub bolts and nuts while vibrating the assembly.
However, when the mounting assistance device 2 is mounted to the assembly 4, it is necessary to use a tool to tighten the nuts 11 and 16 to fix the eccentric disc 12 to the clamping member 10 and to maintain the tightened state, which is complicated. Accordingly, it has been desired that the mounting operation of the mounting assistance device 2 (the vibrating device 18) should be carried out more efficiently.